Press



APPLICATION FILED JUNE l3.-I9I7.

Imaan/1770?' (eovZgeE PWa/iney, by P50011# awwr- G. E. WHITNEY.

' PRESS.

APPLICATION FILED )UNE I3. I9II.

Patented Sept. 23, 1919.

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G. E. WHITNEY.

PRESS.

APPLICATION FILED JUNE I3, I9I7.

IutentedSept. 23, 1919.

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UNITED STATES PATENT OFFICE.

GEORGE E. WHITNEY, 0F BRIDGEPORT, CONNECTICUT, ASSIGNOR TO THE INTERNA- TIONAL PAVEMENT COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION 0F CONNECTICUT.

PRESS.

Specification of Letters Patent.

Patented Sept. 23, 1919.

To all whom t may concern.'

Be it known that I, GEORGE E. WHITNEY, a citizen of the United States, and a resident of Bridgeport, in the county of Fairfield and State of Connecticut, have invented an Improvement in Presses, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention pertains to improvements in presses, and more particularly, though not exclusively to improvements in molding presses adapted to form compressed units from a plastic mass at relatively high Speed.

In the drawings, which show a preferred construction of one embodiment of my invention;

Figure 1 is a diagrammatic vertical longitudinal section.

In Figs. 2 and 3 I have shown diagrammatic sections in the same plane as in Fig. 1, showing the molding instrumentalities in their different relative positions;

Figs. 4 through 14 illustrate a preferred type of valve mechanism for use in connection with the press shown in Fig. 1.

In molding presses one of the principal speed restrictive features has been the change of relative positions of the mold, mold cover, and mold filling means. It has been the usual practice heretofore to utilize a rotary mold or to use a mold and mold cover one of which is fixed, while the other reeiprocates into three positions; the first, for filling the mold; the second, for covering the mold during the pressing operation; and the third, for uncovering the mold for ejecting the compressed product.

While both of the before described practices are satisfactory for many purposes, each has its disadvantages, the rotary mold in that the weights of the part-s are very heavy to stop and start when operating at any considerable speed, and the second in that the distance through which the moving element must be moved is considerable.

p Among the objects of the present invention is to provide a molding press wherein the distance through which the' heavy reciprocating parts must be moved is minimized.

In the preferred embodiment of my invention selected for purposes of illustration, I have shown a mold 2O formed in a reciprocable mold block 21 and carrying the mold plunger 22. Above the mold block 21 I have shown a reciprocable element 23, commonly known as a sliding head, and comprislng the pressure block 24 and the feedlng neck 25. The sliding head 23 and the sliding mold block 21 are each preferably rectilinearly reciprocable to two positions, thereby providing three relative positions for filling, pressing and emptying the mold. The paths of reciprocation are preferably parallel as shown, thereby providing the position shown in Fig. 1 for lling the mold, the position shown in Fig. 2 for pressing the contents of the mold, and the position shown in Fig. 3 in which the mold is uncovered for the purpose of ejecting the compressed contents thereof.

I prefer to move the mold cover, or sliding head, by pressure fiuid, and to this end I have shown a pressure fiuid cylinder 26, having a piston 27 connected by piston rod 28 to the sliding head 23, a similar cylinder 29 having a piston 30 and piston rod 31 connected to the sliding mold block 21.

I prefer to perform the ejection of material from the mold by pressure fluid, and to this end I have shown a cylinder 32, having a piston 33, piston rod 34, and connecting rod 35 for rocking the ejecting lever 36 fulcrumed at 37 and forked at 38 to receive the mold plunger 22, while permitting reciprocation of the latter with the mold block 21.

The amount of material admitted to the mold during the filling operation controls the size of the finished product, and to this end I have shown a feed rod 39 connected to the lever 38, and having at its upper end a feed nut 40 of the usual type. I preferably impart pressure to the contents of the mold by a positive fixed throw mechanical pressure actuator, and to this end I have shown an eccentric 41 carried by the main shaft 42 of the press and engaging an eccentric strap 43 slidably engaging the bottom.

of a rectilinearly reciprocable element 44 herein shown as a hydraulic cylinder slidable in guides 45-46 in the frame of the machine. The hydraulic cylinder 44 is provided with a ram 47 and a displacingplunger 48, the chamber 49 of the hydraulic cylinder 44,being preferably filled with a confstantbodyolf liquid, andthe piston 48prefgage the rear cylinder headY 54 ofthe cylinder 51 and thus to limit the extent to which elastic pressure fluid in the cylinder 51 presses the displacing plunger 48 into the liquid in the 'chamber 49.' To permit reciprocation of the cylinder 51 with the hydrauliccylinder 44, I have shown a conduit `v 55 for elastic pressure fluid, said conduit 55 being reciprocable in a stuffing boX 56 at the termination of the stationary portion of the pressure fluid supply actuator.

A full description of the details of the valve mechanisms for admitting and eX- Vhausting pressure fluid from the cylinders 26, 29, and 32 disclosure.

The operation of machine is as follows: Assuming the machine to be in the position shown in Fig. y1 and the neck 25 to be filled'with material, the mold 20 will have lis not essential to the kpresent been charged, pressure fluid will then be admitted to the front of the cylinder 26, whereretracting the sliding head until it assumes the position shown in Fig. 2, the" mold 20 being covered by the pressure block 24. The eccentric 41 will now apply pressure to the contents of the mold. When a predetermined pressure has been reached, the pressure of the liquid in the cylinder 44 will exceed the pressure of the elastic pressure fluid in the cylinder 51, and the piston 50 will be pressed back, thereby permitting the displacing plunger 48 to retract, thereby permitting the descent of the ram 47 in the cylinder 44, permitting the mold plunger to stop on its pressing movement while the motion imparted to the'cylinder 44 by the eccentric 41 continues. After the eccentric 41 has passed its center position, the cylinder 44 will be lowered,'permitting the piston 50 to move forward in the cylinder 51 until the spring 53 abuts against the cylinder head 1 54. The rain 47 will then stop ascending in admitted to the rear end ofthe cylinder 29,

thereby moying the mold block 21 forward tothe position shown in Fig. 3, Aafter `which ,steam Ais admitted tothe front of kthe ejecting cylinder 32, thereby rocking the lever 36 about the fulcrum 37, elevating the mold plunger 22 until it is flush with the top of the mold block 21, thereby ejecting the contents ofthe mold. The elastic fluid pressure is'then exhausted from the front of the cylinder 26 and `from the -rear of the cylinder 29, while pressure fluid is admitted 'to the rear of the cylinder 26 and-tcithefrontof the cylinder 29, thereby causing the mold and sliding head to assume the relative position shown in Fig. 1. Pressure fluid is ythen exhausted from the front of the cylinder 32 to permit the mold plunger 22 to drop to the position shown in Fig. 1, thereby again filling the mold, and completing one cycle of operation of the press. v

Theuse of mold block and sliding-(head, each having two positions but providing three relative positions of the two elements,Y

is very advantageous because of its simplicity and because of the relatively short distance through which each of these elements need travel, thereby greatly reducing the likelihood of breakage of the press while permitting its operation at high speed.

The combination of a fixed throw mechanical pressure actuator with a variable stroke mold plunger with directly linterposed elastic pressure fluid determined Vhydraulic relief means is of marked advantage in providing a simple and effective pressure determining system which is notspeed restrictive, is notsubject to breakdown, and

does not in any way unbalance the resolution of forces between the fixed throw pressure actuator and the mold plunger.

It will be understood that the cylinders 26, 29 and 32 are carried by any suitable bracket which is preferably connected to the frame of the press. c

While I have shown the drawings and have described one specifi-c embodiment of the preferred construction of my invention, it will be understood that major changes involving omissions, alterations and reversal of parts, and changes in the mode of operation may be made without departing from the scope of my invention, which is.

best defined in the following claims .1. A molding press, comprising fin combination a mold reciprocable .into two vpositions, a mold cover reciprocable into Ytwo positions and automatic actuating mechanism for shifting said mold and mold cover.

.2. molding press, comprising lin combination a mold block slidable into .two Vpositions, a sliding head having a pressure vblock and a mold filling neck, said sliding head being reciprocable into two 1positions, andmeans for shifting. said mold block and sliding headinto three relative positions to provide registration of ysaid mold filling neck with the mold, registration of said lpressure block :with said :mold and uncoirering of said mold for ejection of the contions, a mold plunger, and pressure fluid tents thereof. means for actuating the ejecting movement 3. A molding press, comprising in comof said mold plunger. 10 bination amold block, pressure fluid means In testimony whereof I have signed my 5 for shifting said mold block into two posiname to this specification.

tions, a sliding head, pressure fluid means for shifting said sliding head into two posi- GEORGE E. WHITNEY.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

